Multi-function stalk switch with zero backlash drive gear pair

ABSTRACT

A vehicle steering column stalk switch includes a multifunction switch lever having a rotatable actuator which drives a first rotatable gear. Gear teeth on the first gear engage gear teeth on a second gear mounted within a housing with zero backlash. The second gear is biased into compliant engagement with the first gear. The biasing is effected by means of at least one leaf contact resiliently cantilevered from conductive elements carried in the housing into engagement with the second gear.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application is related to three other co-pending applications, U.S.patent application Ser. No. 09/533,716 for “MULTI-FUNCTION SWITCH LEVERAPPARATUS” and Ser. No. 09/533,718 for “VEHICLE FOG LAMP INTERLOCKSWITCH APPARATUS” and Ser. No. 09/534,426 for “SWITCH APPARATUS FORACTUALIZING A PLURALITY OF ELECTRICAL CIRCUITS”, all filed on Mar. 23,2000.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to switches and, more specifically, tovehicle steering column mounted switches for controlling vehicleoperating circuits and components.

2. State of the Art

The evolution of steering column switches in motor vehicles has beentoward greater integration of functions in a single switch lever.Previously, a plurality of individual switches, each controlling asingle vehicle function, i.e., turnsignals, windshield wipers,headlights, etc., were mounted on the vehicle dashboard. Currentsteering column switch levers are designed to control a variety offunctions for vehicle operating circuits or devices, such as turnsignalsand hazard lights, high beam and low beam headlights with optionalflash-to-pass, parking lights, fog lights, windshield wiper and washfunctions, including multi-speed wipers with or without intermittentdelay.

Typically, a steering column stalk switch includes a single lever orstalk pivotally mounted on one side of a housing attached to the vehiclesteering column in an easily accessible position for access by thedriver of the vehicle. The lever is gimballed at one end in housing soas to move in one and, typically, two mutually separate planes. Further,the lever may be provided with a rotatable end cap, and/or a slidablemember movable along the longitudinal axis of the lever to controladditional vehicle operating circuits. An intermediate member on thelever may also be rotatable to control another vehicle circuit ordevice. Actuators are mounted in the housing and, in response tomovement of the lever in different directions or planes, rotation of theend cap, or movement of the slidable member, or rotation of theintermediate member on the lever, move a switching member carryingcontacts between various switching positions to effect the switching ofelectrical connections for a particular vehicle operating circuit.

In some vehicles, particularly vehicles manufactured in Europe and/orJapan, two steering column stalk switches are provided, one mounted onthe left side of the steering column and one on the right side of thesteering column. The various vehicle operating circuits or devicesdescribed above are split between the two stalk switches, with the leftstalk switch typically controlling vehicle headlight, parking light, foglight, flash-to-pass operation as well as turnsignal operations. Theright mounted stalk lever typically controls windshield wiper, mist andwash devices.

However, regardless of whether one or two stalk switches are employed ina vehicle, vehicle design constraints require that the stalk switchlever and the housing assembly be as small as possible while at the sametime providing easy access to and movement of the various switches onthe stalk switch(es).

It is common in stalk switch design to have a rotatable actuator, suchas a rotatable end cap mounted on an outer end of a stalk switch leverto rotate a drive gear mounted within the stalk switch housing. Thedrive gear engages a mating gear which carries or is otherwise coupledto an electrical contactor carrying one or more contacts which aredisposed for selective engagement with conductive elements or traces ona substrate or printed circuit board mounted within the housing to openand close electrical circuits upon movement of the contactor due torotation of the end cap.

However, due to the multiple functions normally combined into a singlestalk switch lever, the gear pair must be multi-axially oriented withthe drive gear rotatable about one rotational axis during one vehicledevice operation, such as a windshield wipe cycle. The same gear mustalso be movable or pivotal about another rotational axis when the leveris pivoted for activating a windshield wash operation and, further, mustbe movable about yet another rotatational axis upon pivotal movement ofthe lever about a different axis for a windshield wiper mist operation.This multi-axis design requires tooth profiles that are complex todesign and manufacture.

Further, accurate timing during movement of the lever and the internalcomponents about the multiple axis or rotation directions must beprecise for a positive tactile feel to the driver and to ensure that thecomponents move the precise amount during each pivotal or rotationalmovement imparted by the lever or end cap.

It is common in gear pair design to provide backlash which is defined asthe amount by which the tooth space of one gear exceeds the tooththickness of a mating gear at the pitch circle of the gears. That is,the space between two teeth on one gear is larger than the width of eachtooth on the mating gear.

This results in looseness in the mating gears which can lead to timinginaccuracies as well as a sloppy tactile feel to the use when operatingthe stalk switch lever in rotation.

Thus, it would be desirable to provide a vehicle steering column stalkswitch having rotative elements operated by mating gears which hasimproved accuracy and a positive tactile feel to a user during rotation.It would also be desirable to provide a drive gear pair for a vehiclesteering column stalk switch lever which has improved accuracy whenemployed in a multi-axially oriented gear pair.

SUMMARY OF THE INVENTION

The present invention is a drive gear pair for a vehicle steering columnstalk switch lever which includes a vehicle steering column stalk switchincluding a housing mountable on a vehicle steering column, a levermovably mounted on the housing, an actuator carried on the lever androtatable with respect to the lever, a first gear having first gearteeth and coupled to the actuator for rotation with rotation of theactuator, a second gear movably mounted in the housing and having secondgear teeth. The first and second gear teeth of the first and secondgears, respectively, are engaged with zero backlash. Conductive elementsare carried on one of the second gear and the housing. A contact iscarried on the other of the second gear and the housing wherein rotationof the actuator causes rotation of the first gear and movement of thesecond gear to selectively engage the contact with selective conductiveelements to open and close electrical circuits therebetween.

In one aspect of the invention, means are provided for biasing the firstand second gears into engagement. According to a preferred aspect, thebiasing means comprises at least one contact formed as a leaf contactresiliently cantilevered from the conductive elements in the housing.The leaf contact biasingly engages the second gear to bias the secondgear into compliant engagement with the first gear.

Counter to conventional gear pair design, the present drive gear pairutilizes mating gear teeth which mesh with zero backlash and zerointerference. This enables a more accurate timing to be devised for avehicle steering column stalk switch apparatus during movement of therotatable portion of the lever.

The use of zero backlash also enables the multifunction stalk switchlever to provide a more positive tactile feel to a user when rotatingthe rotatable portion of the lever through various defined detentpositions. The use of zero backlash also enables the multifunctionswitch lever apparatus of the present invention to be constructed with amore simplified assembly method.

BRIEF DESCRIPTION OF THE DRAWING

The various features, advantages and other uses of the present inventionwill become more apparent by referring to the following detaileddescription and drawing in which:

FIG. 1 is a perspective view of a steering column stalk switch apparatusaccording to the present invention;

FIG. 2 is a bottom elevational view of the apparatus of FIG. 1 shown inan assembled state;

FIGS. 3A and 3B are exploded perspective views of the housing portion ofthe stalk switch apparatus shown in FIG. 1;

FIG. 3C is an exploded perspective view of the headlight/turnsignalstalk switch lever shown in FIG. 1;

FIG. 3D is an exploded perspective view of the wiper stalk switch levershown in FIG. 1;

FIG. 4 is a plan elevational view of the back housing shown in FIGS.1-3A;

FIG. 5A is a longitudinal cross section view generally taken along line5A—5A of FIG. 1;

FIG. 5B is a bottom perspective view of the headlight/turn signal leverengaged with the linear rack;

FIGS. 6A, 6B, 6C and 6D are pictorial representations of different camprofiles employed in the headlight/turnsignal stalk switch shown inFIGS. 1 and 3B;

FIG. 7 is a longitudinal, cross sectional view of the detent surfaces inthe spacer ring shown in FIG. 3C;

FIG. 8 is a bottom elevational view of the turnsignal carrier shown inthe center position;

FIG. 9 is a bottom elevational view of the turnsignal carrier in a lefthand turn position;

FIG. 10 is a top perspective view of the wiper switch mounted on thegrid assembly;

FIG. 11 is a bottom perspective view of the wiper switch mounted on thegrid assembly;

FIG. 12 is a side elevational view of the wiper switch shown in FIG. 3D;

FIG. 13 is a bottom elevational view of the radial rack and printedcircuit board of the wiper switch shown in FIGS. 3D and 10-12;

FIG. 14 is a cross-sectional view generally taken along line 14—14 ofFIG. 10;

FIG. 15 is a partially cross-sectioned, side elevational view of thewiper switch lever of FIG. 10; and

FIG. 16 is an enlarged partial view of the gear pair shown in FIG. 15.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the drawing, and to FIGS. 1-14 in particular, there isdepicted a steering column stalk switch apparatus 10 which is mountableon a vehicle steering column, not shown, and operative to control thevehicle exterior lighting, windshield wiper and windshield washfunctions and hazard flash functions, and to control of the intensity orbrightness of the interior instrument panel back lighting.

The steering column stalk switch apparatus, hereafter referred to as the“switch apparatus”, includes a housing assembly 12 formed of a backhousing 14 and a front cover 16 which is interlockingly engagable withthe back housing 16 and mountable by conventional means to a vehiclesteering column, a headlamp/turnsignal lever assembly 18, a windshieldwiper/wash/mist lever assembly 20 and a hazard flasher denoted generallyby reference number 22.

The back housing 14 is formed as a one-piece, molded plastic memberhaving a bottom wall 32 with a stepped configuration and upstanding sidewalls 34 extending from various peripheral edges of the bottom wall 32and forming cavities on the back housing 14 for receiving variouscontrol elements, as described hereafter.

As generally shown in FIGS. 1, 2, 3A and 4, the back housing 14 includesa first cavity 36 containing a headlamp contact grid 38 insert molded inthe bottom wall 32 and an adjacent portion 40 containing apertures forreceiving terminals of a headlamp beam change grid described hereafter.

Adjacent to the first cavity 36 are mounting flanges 44 which receive ahazard carrier 46 forming part of the hazard flasher 22. The hazardcarrier 46 is movably biased relative to the back housing 14 by aplunger 48 and a biasing spring 50 which seat in a tubular member 52extending from the bottom wall 32 of the back housing 14. A bifurcatedleaf contact 54 is heat staked to mounting pins on the hazard carrier46. Contact ends of the leaf contact 54 are adapted to engage a contactgrid mounted on a printed circuit board which carries a flasher relay asis conventional. Movement of a hazard carrier button 56 and the entirehazard carrier 46 causes the leaf contact 54 to complete an electricalcircuit between various contacts or conductive traces on the relayprinted circuit board thereby providing an output signal to a hazardsense contact 58 which is mounted in recesses in the bottom wall 32 ofthe back housing 14. The hazard sense contact 58 terminates in a bridge60 formed of a plurality of opposed resilient contact arms which definea slot therebetween.

A latch pin 62 rides in a slot 64 seen in FIG. 3B in the hazard carrier46 to control latching of the hazard carrier 46 in the depressedposition and unlatching upon subsequent depression of the hazard button56 in a conventional manner.

As also shown in FIG. 4, a plurality of additional recesses are formedin a generally central portion of the back housing 14 to receiveadditional clip bridges 66, each in the form of a unitary electricallyconductive member having at least one pair and preferably a plurality ofpairs of spaced resilient arms, each pair or groups defining a singleslot therebetween for receiving a terminal. The rightmost end portion ofthe back housing 14, in the typical driver orientation shown in FIG. 4,includes a plurality of terminal receiving apertures 72 and a generallyarcuate recess 74.

As shown in FIG. 2, first and second connector receptacles 78 and 80,respectively, are formed on and extend from the bottom wall 32 of theback housing 14. Each receptacle 78 and 80 includes apertures forreceiving terminals therethrough from various components mounted in theback housing 14 as described hereafter. In addition, a plurality ofterminals 82 are formed in the first connector receptacle 78. Theterminals 82 are connected to various traces in the headlamp contactgrid 38. Two additional terminals 84, also connected to portions of theheadlamp grid 38, are located adjacent to the first connector receptacle78. In this manner, a plurality of individual connectors from thevehicle body wiring harness may be easily interconnected to theterminals in the back housing 14 for connection of the variouscomponents of the switch apparatus 10 to the vehicle electrical systemfor control of specified vehicle components as described hereafter.

As shown in FIGS. 1 and 4, a one piece grid assembly 88 has a firstcontact grid 90 insert molded in a rigid insulating carrier or body.Leads 91 extend from the contact grid 90 to terminals 92 projectingexteriorly of the bottom wall 32. Another grid assembly 91 includingconductive traces is insert molded in another portion of the gridassembly 88.

The grid assembly 88 has terminals 89 extending from apertures 87, shownin FIGS. 10 and 11, which engage the clip bridges 66 to electricallyconnect the hazard carrier 46 to the conductive contact grid 90 and,then, to the terminals 92 in the receptacle 80. The terminals 89 assistin mounting the grid assembly 88 as a part of the back housing 14.

Also forming a part of the grid assembly 91 is a contact grid 93designated for windshield wiper/mist/wash operation, as describedhereafter. The second contact grid 93 includes individual leaf contacts94, 95, 96 and 97. A further description of the operation of the leafcontacts 94-97 will be provided hereafter in conjunction with adescription of the windshield wiper/wash lever 20.

Finally, a post 98 extends from one end of the carrier bodies of thegrid assembly 88 and receives the wash/mist actuator as describedhereafter.

The front cover 16, as shown in FIGS. 1 and 3A, is also formed of aone-piece, molded plastic body having a shape complementary to the shapeof the back housing 14. The front cover 16 provides pivot connections tothe headlamp/turnsignal lever 18 and the windshield wiper/wash lever 20as described hereafter. Keyed posts 99 project from one edge of thefront cover for orienting the front cover 16 on the steering column wheninserted into mating slots in a steering column mounting bracket.Mounting flanges 101 also project from the front cover 16 for alignmentwith apertures in the steering column mounting bracket, not shown.Additional features of the front cover 16 will be described inconnection with the various operative elements of the switch apparatus10 with which such features interact.

Referring now to FIGS. 1, 3A, 3B, and 4-7, the detailed construction ofthe headlamp/turnsignal lever 18 will now be provided. A turn carrierbase 110 is mountable by means of opposed pairs of latch arms 112 intoapertures in the bottom wall 32 of the back housing 14 generally locatedin the first cavity and adjacent portions 36 and 40. The turn carrierbase 110 includes a pair of arcuate walls 114 which project upwardlyfrom a support wall 116. The arcuate walls 114 and the support wall 116support a pair of depending legs 322, only one of which is shown in FIG.3A on a turnsignal carrier 320. The legs 118 slidably rest on thesupport wall 116 and are disposed adjacent to the arcuate walls 114 toprovide pivotal movement of the turnsignal carrier 320 between a centerneutral position and opposed left turn and right turn positions.

A pair of recesses 122, only one of which is shown in FIG. 3A, aredisposed adjacent to the arcuate walls 114 and receive opposed pivots124 on a fog lamp lever 126. The pivots 124 pivotally mount the fog lamplever 126 to the turn carrier base 110. The fog lamp lever 126 has acentrally located pad 128 depending from a center leg portion 130. Whenthe fog lamp lever 126 is pivotally mounted in the recesses 122 in theturn carrier base 110, the pad 128 is disposed within an aperture 132 inthe support wall 116 of the turn carrier base 110 so as to be accessiblethrough the aperture 132 to movement of the end of a shaft extendingthrough the lever 18 as described hereafter.

Hollow posts 134 are also formed along one end of the turn carrier base110 for receiving interconnecting pins depending from the front cover 16to position the turn carrier base 110 relative to the front cover 16.

The turnsignal carrier 320, which will be described in greater detailhereafter in conjunction with operation of the headlamp/turnsignal lever18 for operation of the vehicle turnsignals, is preferably in the formof a one-piece, molded plastic body which includes a tubular sleeve 326mounted in a leg extending between an upper portion of the dependinglegs 118. The sleeve 326 receives a lever plunger 136 shown in FIG. 3Chaving a spherical endform which is seated in one end of the sleeve 326.A projection, not shown, depends from the front cover 16 into the otherend of the sleeve 326 to pivotally mount the turnsignal carrier 120 inthe housing 12.

The lever plunger 136 is biased into the sleeve 326 by a biasing memberor spring 140 which seats in a tubular sleeve 141 formed at one end of ahollow lever 142. The lever 142 is preferably in the form of aone-piece, unitary, molded plastic body having a pair of transverselyextending trunnions 144, only one being shown in FIG. 3C, whichpivotally seat within apertures formed in the depending legs 118 on theturnsignal carrier 320. When the trunnions 144 are mounted in theapertures in the depending legs 118, the sleeve 141 is generallycoaxially aligned with the sleeve 326 on the turnsignal carrier 320. Inthis manner, the headlamp turnsignal lever 142 is pivotally mounted forrotation in two angularly disposed planes. Preferably, the lever 142 ismounted for pivotal movement in two perpendicular opposed planes about afirst axis extending between the trunnions 144 and a second axisextending through the sleeve 141, the lever plunger 326 and the sleeve134 on the turnsignal carrier 320.

As also shown in FIG. 3C, the lever 142 is provided with a flash-to-passpaddle 146 which projects angularly from one end of the lever 142. Inaddition, a mounting arm 148 with a through slot 150 depends from oneend of the lever 142 generally below the paddle 146. The mounting slot150 is coaxially aligned with a through bore extending through the lever142 from one end adjacent to the mounting arm 148 and an opposed endforming a seat generally spaced from an opposed exterior end 156 of thelever 142.

As shown in FIGS. 3C, 5A and 5B, a printed circuit board 160 carryingconductive traces individually connected to a series ofcircumferentially spaced resistors is mounted on the seat within the end156 of the lever 142. A leaf contact 162 having a pair of leaf contactpads 164 mounted at the end of two spaced arms, is fixedly mounted, suchas by heat staking, in one end of an instrument panel lamp dimmer ring166. Rotation of the dimmer ring 166 causes the contact arms 164 to wipeacross the conductive traces on the circuit board 160 thereby varyingthe amount of resistance supplied to the instrument panel lamp circuit.A pair of wires 168 are connected, such as by soldering, to the circuitboard 160 at one end and pass through the first end of the lever 142exteriorly of the back housing 14 to the two additional terminals 84 onthe exterior surface of the bottom wall 32 of the back housing 14.Terminal connections on the end of the wires 168 connect to terminals 84which are in turn connected via conductive traces on the grid assembly88 to selected first connector terminals 82. The wires 168 are protectedby a cover 170, shown in FIG. 3B which snaps on the exterior surface ofthe back housing 14.

A through bore 172 is formed internally within the dimmer ring 166 in asolid central member 174 mounted or formed within the outer periphery ofthe dimmer ring 166. The outer periphery of the dimmer ring 166 may beformed with surface gradations, such as spaced projections, providing aneasily rotatable finger engagement surface.

The opposed end of the central member 174 is provided with at least oneand, preferably, a pair of spring seats which receive biasing springs176. A plunger 178 is mounted at the opposite end of each spring 176. Atleast one of the plungers 178 rides against an arcuate detent surface180 formed on one end of an intermediate housing 182. The other plunger178 rides on a smooth end portion of the housing 182. Two diametricallyopposed plungers 178 are preferably employed, even through only oneplunger 178 engages the detent surface 180, for force equalizationduring rotation of the dimmer ring 166. The intermediate housing 182 ischaracterized by a generally cylindrical portion having the one end 180and an opposed end 184. A tubular shaft 186 projects from the first end180 and has a hollow bore extending therethrough. The bore also extendsthrough the tubular portion of the intermediate housing 182. A pair ofguide fingers 188 project from the first end 180 concentrically aboutthe shaft 186 and engage recesses formed in the central member 174 inthe dimmer ring 166 to key the orientation of the intermediate housing182 to the dimmer ring 166. Lock projections 190 are formed on theexterior surface of each guide finger 188 and snap around one end of thecentral member 174 in the dimmer ring 166 to secure the intermediatehousing 182 to the dimmer ring 166.

The detent surface 180 which is formed with a series ofcircumferentially spaced projections provides discrete tactile positionsfor the dimmer ring 166 to control the intensity of the instrument panellamp(s) as described above.

A guide rail 192 is formed on the exterior of the tubular portion of theintermediate housing 182. The guide rail 192 engages a slot in an endcap as described above.

A spacer ring 200, shown in detail in FIGS. 3C and 7 is in the form of atubular body having an internal through bore which is coaxiallymountable over the tubular portion of the intermediate housing 182.Internal projections 201, formed within the bore of the spacer ring 200engage diametrically opposed apertures 202 in the intermediate housing182 to fixedly lock the spacer ring 200 to the intermediate housing 182.

A detent surface 204 including three detents 206, by example, isprovided on a portion of the interior surface of the bore in the spacerring 200. Each detent 206 extends substantially along the entire lengthof the spacer ring 200; but has an intermediate step 207 dividing eachdetent into two coaxial, but radially offset shown in FIG. 7.

A shaft 210 extends through the joined spacer ring 200 and theintermediate housing 182, the dimmer ring 166 and the lever 142, asshown in FIGS. 3C and 5. The shaft 210 includes a first large diametershaft portion 212 and a first end portion 214 of a smaller diameter. Aflat or other key shaped member 216 is formed at the juncture of thefirst and second shaft portions 212 and 214 for keyed engagement with adrive gear described hereafter.

The opposite end of the shaft 210 is formed with a transverselyextending tubular sleeve 218 having opposed end bores which individuallyreceive a biasing member 220, such as a compression spring, and amovable plunger 222. As can be seen in FIG. 5, the plungers 222 projectdiametrically and transversely outward from a longitudinal axis of theshaft 210.

A pair of spaced fingers 230 project coaxially with the longitudinalaxis of the shaft 210 from the sleeve 218 and are adapted to engage aninterior bore 232 in an end cap 234. The interior bore 232 is formedwithin a mounting sleeve 236 having a pair of spaced legs 238, eachcarrying an aperture 240. The apertures 240 align with the bores in thesleeve 218 to secure the end cap 234 to the shaft 210. The alignedapertures 240 in the end cap 234 and the bores in the sleeve 218 allowfor insertion of the biasing spring 220 and the plunger 222 therein.

When the dimmer ring 166 is mounted on the shaft 210 and the spacer ring200 is mounted about the intermediate housing 182, the shaft 210projects through the aligned bores in the aforementioned components,such that the plungers 222 will be biased outward from the sleeve 218and ride in a cam profile 224 which allows operation of the fog lightson the vehicle only in certain headlamp operative states. Variousconfigurations of the cam profile 224 may be provided as shown in FIGS.6A, 6B, 6C and 6D. The cam profile 224 shown in FIG. 6A depicts thevarious positions of one of the plungers 222 in the cam profile 224.

Since the end cap 234 is securely coupled to the shaft 210, the end cap234 is freely rotatable relative to the lever 142, the dimmer ring 166,the intermediate housing 182 and the spacer ring 200. Rotation of theend cap 234 and the shaft 210 about the longitudinal axis of the shaft210 moves one of the plungers 222 across the detents 206 in the detentsurface 204 in the spacer ring 200. Three detent positions are definedas shown in FIG. 7, respectively defining headlamp “off”, “park” and“on” or “low beam” light operative states. Further, the end cap 234 andthe shaft 210, as well as the drive gear coupled to the second diameterend portion 214 of the shaft 210 are capable of longitudinal movementwith respect to the lever 142, the intermediate housing 182 and thespacer ring 200. This longitudinal movement is controlled by the camprofile 224. Only in certain rotated positions of the end cap 234 asdefined by the detents 206 in the spacer ring 200, is the plunger 222capable of longitudinal movement axially outward from the lever 142moving the plunger 222 into the stepped portion of the cam profile 224.This position, as described hereafter, provides a connection to thevehicle fog lights enabling activation of the fog lights only when thevehicle headlights are in the “park” and “on” positions as shown for thecam profile 224 in FIG. 6A. Alternate cam profiles 244, 246 and 248 areshown in FIGS. 6B, 6C and 6D, respectively. Each of these cam profiles244, 246 and 248 provides a different headlamp-fog light relationship.In FIG. 6B, the cam profile 244 allows the plunger 222, the shaft 210,and the end cap 234 to be pulled axially outward only when the vehicleheadlights as defined by the rotated position of the end cap 234 are inthe “on” position. From this front fog lights “on” position, the end cap234 may be further rotated to turn on the rear fog lights.

The cam profile 246 in FIG. 6C allows activation of the vehicle frontfog lights only when the vehicle headlights are “on”. The cam profile248 in FIG. 6D is a cam profile for a vehicle which does not have frontor rear fog lights.

As shown in FIGS. 3C and 5A, the second smaller diameter end portion 214of the shaft 210 is slidable through a bore 250 formed in a sleeve 252of a drive gear 254. The internal bore 250 in the sleeve 252 includeskey slots alignable with the key members 216 on the shaft 210 to key theangular position of the gear 254 to the shaft 210.

The drive gear 254 includes a collar 256 shown in the form of asector-shaped projection. A plurality of gear teeth 258 projectangularly from the end of the projection 256. By way of example only,each gear tooth 258 has an elongated stem terminating in a spherical endportion as described in greater detail in U.S. Pat. No. 5,259,262, theentire contents of which are incorporated herein by reference.

The gear teeth 258 on the drive gear 254 engage a linear rack 262, shownin FIG. 3B, in the form of a linear arrangement of spaced recessesformed on a carrier 264. An actuator post 266, the purpose of which willbe described hereafter, projects outwardly and upwardly from one side ofthe carrier 264.

An electrically conductive terminal grid 268 is fixedly mounted, such asby heat staking, to the bottom surface of the carrier 264. The terminalgrid 268 includes a plurality, preferably three, leaf contacts 270. Theleaf contacts 270 slide along the various conductive traces in theheadlamp contact grid 38 seen in FIG. 4, which are mounted on the bottomwall 32 of the back housing 30 as described above. These traces areconnected to terminals on the back surface of the housing to providepower to the various headlamp operating circuits depending upon the modeof operation of the headlamp/turnsignal lever 18.

A three point electrical contact 272 is movably mounted on one end ofthe carrier 268 and normally biased outwardly from the carrier 268 by abiasing compression spring 274. The three point contact 272 controlsactuation of the vehicle park lamps when the end cap 234 is rotated tothe park lamp “on” position.

A side contact 276 is also mounted on the carrier 264. The side contact276 is held normally open by the center leg portion 130 of the fog lamplever 126 when the shaft 210 and end cap 234 are in the normal operatingposition; but activates the vehicle fog lights when moved to the closedposition on axially outward movement of the end cap 234 and shaft 210 asdescribed above. This movement removes the pivoting force on the foglamp lever 126 allowing the lever 126 to pivot closing the contact 276with one of the contacts 270 to complete a circuit through the contactgrid 38 to activate the vehicle fog lamps.

Adjacent to the linear rack carrier 264 in the first major cavity 36 ofthe back housing 14, is a beam change grid assembly 278 which is mountedby means of terminals 280 depending from a housing 282 carrying theoperative components of the beam change assembly, which terminals 280engage apertures formed in the bottom wall 32 of the back housing 14.

A beam change carrier 284 is pivotally mounted in the housing 282. Thebeam change carrier 284 includes a pair of depending legs whichlatchingly engage receivers 288 formed in the housing 282. Returnsprings 290 are mounted between the legs 286 and the bottom end of thereceivers 288 for biasing the beam change carrier 284 to an oppositepivoted position depending upon which spring 290 is compressed. Apivotal toggle switch 292 is pivotally mounted in the beam changecarrier 284 on a centrally located transversely extending post. Toggleswitch 292, when the beam change carrier 284 is biasingly mounted in thehousing 282, has a pointed end adapted to engage a beam change actuator294. The actuator 294 includes a pair of detents 296. A beam changecontact 298 is biasingly mounted by means of a spring 300 to one side ofthe beam change actuator 294 and is positioned to engage a contact grid302 insert molded or heat staked to the housing 282. A headlamp contact304 is fixedly mounted at one end to the beam change grid housing 282and has an opposite contact end spaced from a contact pad on the grid302 exposed to a back wall of the housing 282. The contact pad on thecontact 304 is normally spaced from the grid 302. However, the contact304 will contact the contact pad on the grid 302 when the end cap 234 isrotated to the park position wherein the projection 266 on the linearrack carrier 264 will slide past the contact 304 moving the free end ofthe contact 304 into contact with the grid 302 on the beam change gridhousing 282.

A spring biased plunger assembly 285 is mounted in the housing 282 andextends outward into contact with a two position detent surface 295formed on the actuator 294. The plunger 285 serves to retain theactuator 294, which is rotatably mounted about post 281 on the housing282, in one of the two detent positions defined by the two detents 295.However, forced movement of the toggle switch 292 through pivotalmovement of the lever 18 toward the driver causes the paddle 146 toengage the upper surface of the beam change carrier 284 resulting in apivotal movement of the beam change carrier 284 in an opposite directionfrom its then current position. This rotates the toggle switch 292causing driven rotation of the actuator 294 to the opposite position.Rotation of the actuator 294 causes a rotation of the beam changecontact 298 bringing the contacts 298 into contact with other conductivetraces 302 resulting in output signals through the terminals 280 toactivate or deactivate the vehicle high beam headlights.

The paddle 146 on the lever 142 engages the top wall of the beam changecarrier 284 when the lever 142 is pulled toward the driver from itsnormal position. This movement forces the beam change carrier 284 toassume an opposite pivoted position wherein the toggle switch 292 isforced over the detents 296 causing the actuator 294 to rotate therebychanging the connections between the ball contacts on the beam changecontact 298 and the conductive traces on the grid 302. When it isdesired to turn to normal low beam headlights, the lever 142 is againpivoted toward the driver causing a reverse action and opposite rotationof the actuator 294 to return the contact 298 to connection with thetraces on the grid 302 associated with low beam headlights.

A pair of flash-to-pass contacts 304 are biased outward from a side wallof beam change carrier 284 by means of biasing springs 306.

Referring now to FIGS. 8 and 9, there is depicted the turnsignalmechanism actuated by rotational movement of the lever 18 about an axisextending through the sleeve 141 shown in FIG. 1. The turnsignalmechanism includes the turnsignal carrier 320 which is rotatably mountedon the turn carrier base 110 by means of a pair of legs 322 which dependfrom a wall 324. The legs 322 rotatably engage the support wall 116 andarcuate walls 114 as described above and shown in FIG. 3A forbidirectional pivotal movement relative to the turn carrier base 110. Asleeve 326 projects from an opposite side of the wall 324 between thedepending legs 322. The sleeve 326 receives the lever plunger 136 andbiasing spring which extend through the sleeve 141 at one end of thelever housing 142 to form a pivot allowing bidirectional rotation of thelever 18 and the turnsignal carrier 320 relative to an axis extendingthrough the front cover 16 in which the lever plunger 324 is seated.

The wall 324 has a pie or sector shape formed of a pair of side walls328 and 330 which project angularly from the sleeve 326. A pair ofinboard walls are respectively mounted on the wall 324 and spaced fromthe side walls 328 and 330, respectively, to form an opening or slottherebetween, each receiving an individual roller plunger assembly 336and 337, respectively. The roller plunger assembly 336 is referred to asa “latching plunger”; while the roller plunger assembly 337 is referredto as a “return plunger”.

Each roller plunger assembly 336 and 337 includes a generally solidplunger body 338 carrying a roller 340 at an outer end. The plunger 338is biased outwardly from each slot by a biasing member 342, such as acoil spring.

The inside surface of the front cover 16 is formed with first and secondcam surfaces 344 and 346, respectively, which oppose the rollers 340 onthe roller plunger assemblies 336 and 337, respectively. The first camsurface 344 is formed with three detents, including a center or neutraldetent 348, a left turn detent 350 and a right turn detent 352. Theturnsignal carrier 320 is normally situated so that the latching plunger336 has the roller 340 disposed in the center or neutral detent 248.However, upon pivotal movement of the lever 18 in a left turn directionor a right turn direction, the latching plunger 336 will ride along thecam surface to either side of the center detent 348 causing acompression of the spring 342 and allowing the roller 340 to traversethe first cam surface 344 until it seats in either the left turn detent350 or the right turn detent 352.

Coincident with pivotal movement of the turnsignal carrier 320 in eitherdirection about the pivot axis extending through the sleeve 326, thereturn plunger 337 will have its roller 340 traverse the second camsurface 346 from a center or neutral detent 354. The second cam surface346 is formed with first and second cam irregularities 256 and 358 whichare intermediately disposed along the length of each portion of thesecond cam surface 346. The first and second cam detents orirregularities 356 and 358 provide a tactile feel to the user prior tothe latch plunger 336 fully engaging one of the left turn or right turndetents 350 and 352. However, when the turnsignal carrier 320 has beenrotated to a position where the roller 340 on the return plunger 337contacts one of the irregularities 356 and 358, the selected turnsignallights will be turned on as described hereafter. However, the biasingspring 342 will bias the return plunger 337 toward the center neutraldetent 354 thereby forcing the turnsignal carrier 320 back to the centerposition deactivating the turnsignal lights as soon as the user releasesthe pivotal force on the lever 18. This enables a driver to brieflyflash the left turn or right turn signal lights without fully engagingthe latch plunger 336 in the left turn or right turn detents 350 and352.

As shown in FIGS. 8 and 9, a pair of cancel members 360 and 362 aremounted on the wall 324. The cancel members 360 and 362 have anidentical shape. According to a unique feature of the present invention,each cancel member 360 and 362 is pivotally mounted on the wall 324between spaced wall portions 364 and 366 formed on the wall 324. An endportion of each cancel member 360 and 362 is pivotally attached to thewall 324 by means of a pivot pin 368 which has an enlarged end disposedon an opposite surface of the wall 324 to mount the cancel members 360and 362 on the wall 324 while allowing pivotal movement of the cancelmembers 360 and 362. A biasing member, such as a spring 370, is mountedbetween a pair of ribs on the wall 324 and acts to bias the cancelmembers 360 and 362 to a neutral position shown in FIG. 8.

A cancel cam 371, typically mounted on the vehicle steering wheel, notshown, engages a cancel pawl 372 upon rotation of the steering wheel ina direction counter to the turn direction. The cancel pawl 372 has anarm portion projecting outwardly from a center portion of the wall 324.The cancel pawl 372 projects outwardly through an opening ordiscontinuity 376, shown in FIG. 1, in the front cover 16.

A pin 378 projects upwardly from the center portion of the cancel pawl372 and rides within a slot 380, shown in FIG. 1 in the top wall of thefront cover 16 to control translation of the cancel pawl 372. Anoppositely extending pin 382 projects from a bottom portion of theintermediate portion of the cancel pawl 372 and rides within a recessshown in FIG. 8 between a center portion and two opposed detent portions385′ and 385 which correspond to fully latched left turn and right turnpositions of the latch plunger 336. The opposite end of the cancel pawl372 is formed with a block-shaped member 384. An inner edge of theblock-shaped member 384 is spaced from the post 378. A return piston anda biasing spring are interposed between one end of a recess in the frontcover 16 and the post 378 and act on the post 378 of the cancel pawl 372to bias the cancel pawl 372 to a center position while permittingpivotal movement of the cancel pawl 372 about the post 378.

As shown in FIG. 8, in a normal non-turnsignal operating condition, thecancel pawl 372 is in a centered position spaced from each from of thecancel members 360 and 362. However, when the turnsignal carrier 320 ispivoted into a left turn or right turnsignaling position, the blockmember 384 on the cancel pawl 372 will be disposed adjacent to one ofthe cancel members 360 and 362 as shown in FIG. 9.

As a driver normally releases the turnsignal lever 18 signal after fullyengaging the lever 18 in a left turn or right turnsignaling position,sufficient rotation of the steering wheel while making a left hand orright hand turn will rotate the cancel cam 371 a sufficient amount topivot the cancel pawl 372 thereby urging the adjacent cancel member 360or 362 in a direction to unlatch the latching plunger 336 from the lefthand or right hand detent position 350 and 352 and to return theturnsignal carrier 322 to the normal centered position shown in FIG. 8.

However, a condition can arise where the driver maintains a force on thelever 18 associated with a left hand or right hand turn while making theturn. This could create a jam between one of the cancel members 360 and362 and the cancel pawl 372 creating the potential for breakage of theserelatively small components.

According to the present invention, the unique provision of the biasingspring 370 and making the cancel members 360 and 362 pivotal as well asproviding the biasing piston 386 and biasing piston spring 388 enablesthe cancel member 360 or 362 immediately adjacent the cancel pawl 372 ina turn position shown in FIG. 9, to pivot out of the way of theblock-shaped member 384 on the cancel pawl thereby enabling the cancelpawl 372 to pass by the cancel member 360 or 362 without breakage ofeither component. The biasing spring 370 ensures that the cancel members360 and 362 are biased to their normal position shown in FIG. 8 afterrelease of force on the lever 18.

Finally, as shown in FIG. 3A, an arm 388 having an internal bore, notshown, is mounted along one side wall 328 of the turnsignal carrier 320.The arm 388 depends downwardly from the wall 328 of the turnsignalcarrier 320 and receives a biasing spring 390 and an electrical contact392 which is preferably in the form of a three point contact as shown inFIG. 3A. In the operative mounting position of the turnsignal carrier320 in the turn carrier base 110, the contact 392 is positioned over thecontact grid 90 on the grid assembly 88, shown in FIGS. 3A and 10,disposed on an upper portion of the grid assembly 88. For convenience,the conductive traces in the contact grid 90 are connected through theleads 91 to terminals on the right hand end of the grid assembly 88 forconnection to a turnsignal cable connector, not shown.

Referring now to FIGS. 10-14, there is depicted the detailedconstruction of the windshield wiper/wash/mist lever 20. As describedabove, the grid assembly 88 which is mounted in the back housing 14 hasan upstanding post 98 on one end portion of the grid assembly.

Starting on the left end of the FIG. 10, the lever 20 includes awash/mist actuator 410 including a hollow, tubular post 412 which isrotatably mountable over the post 98 on one end of the grid assembly 88.A second, shorter, hollow, tubular sleeve 414 is also integrally mountedon the wash/mist actuator 410 adjacent to the post 42. A generallyelongated, diamond-shaped tubular member 416 is also integrally formedadjacent to the post 412 and extends upward therefrom as a centeringmember.

An arm 418 projects radially outward and then arcuately from the post412. The arm 418 terminates in a depending flange 420 which ispositioned to be slidably disposed between the first and second leafcontacts 94 and 95 on the second contact grid 93 of the grid assembly 88as shown in FIG. 13. The arm 418 also, when the post 412 is mounted onthe post 98 of the grid assembly 88, is positioned to ride beneath anannular flange 422 formed on the housing of the grid assembly 88.Further, the end of the arm 418 engages the elongated end of the centerleaf contact 95.

Rotation of the lever 20 in a generally downward direction with respectto the normal mounting orientation of the lever 20 on the vehiclesteering column causes the lever 20 to pivot about the wiper carrierpivot 448 resulting in rotation of the wash/mist actuator 410 in adirection to separate the arm 418 from contact with the center leafcontact 95 on the grid assembly 88. This enables the center leaf contact95 to spring into contact with the center conductive trace 430 on theradial printed circuit board 426 to complete a circuit.

It should also be noted that the post 412 is also mounted for transversemovement along the post 98 thereby enabling the entire wash/mistactuator 410 to translate along the post 98 in response to pivotalmovement of the lever 20 as described hereafter.

As noted above, the printed circuit board 426 has an arcuate shape andcarries three conductive traces 428, 430 and 432. It should be notedthat the radially outermost trace 432 is formed of a number ofresistors.

The printed circuit board 426 is mounted on a radial rack 436 whichincludes a plurality of arcuately disposed tooth receiving recesses 438which are molded as part of a carrier or body. As shown in FIGS. 15 and16, each recess bore 38 in the radial rack 436 has a straight lineprofile formed of opposed faces 437 and 439 which project from a bottomland 441. The faces 439 of each recess 438 are disposed at apredetermined pressure angle 443, such as 10° by example. It will beunderstood that the profile of each recess 438 and the radial rack 436may take any other form, such as a conventional involute gear toothedend space form.

An arm 440 projects outward from one end of the radial rack 436 andterminates in a tubular sleeve 442 having a through bore extendingtherethrough which is designed to rotatably fit over the upper end ofthe post 98 on the grid assembly 88 above the wash/mist actuator 410 asshown in FIG. 11. A stop rib 444 projects from a back surface of theradial rack 436 and acts as a rotation stop to limit rotation of theradial rack 436 in one direction. Rotation of the radial rack 436 in anopposite direction is limited by contact between the outer end of theradial rack 436 and an interior shoulder formed in the back housing 14.

Next, a wiper carrier pivot 448, shown in FIG. 3D, is provided in theform of a one-piece, unitary, molded plastic body. The wiper carrierpivot 448 has a tubular end 450 having a pin 452 of irregular shapewhich is complementary to the shape of the bore in the sleeve 414 on thewash/mist actuator 410. Preferably, the bore in the sleeve 414 and thecross section of the post 452 has a generally triangular cross sectionso as to enable the wash carrier pivot 448 to be mounted in only oneorientation in the sleeve 414.

The wiper carrier pivot 448 also includes a mounting portion carrying atubular, hollow pivot sleeve 454 and a pair of depending mounting legs456 each having an aperture 458 therein. The sleeve 454 fits within anaperture 455 formed in the front cover 16 as shown in FIG. 3C topivotally mount the wiper carrier pivot 448 to the front cover 16.

The mounting legs 456 and apertures 458 are alignable with a pair oftransversely extending trunnions 460, only one of which is shown in FIG.3D, which trunnions are formed on one end of a wiper lever 462. Thetrunnions 460 are generally adjacent to the tubular sleeve 464 whichreceives a lever plunger return spring 466 and a lever plunger 468. Thelever plunger 468 biasingly seats within a bore formed on the undersideof the wiper carrier pivot 448 such that the lever plunger return spring466 biases the wiper lever 462 to a normal position and willautomatically return the wiper lever 462 to the normal position afterforce on the lever 20 pulling the lever 20 toward the driver to actuatea windshield wash and wiper operation is released.

Further, a pair of arms 465 are formed at one end of the wiper lever462. With the wiper lever 462 rotatably mounted via the trunnions 460 inthe mounting apertures 458 of the mounting legs 456 of the wiper carrierpivot 448, the arms 465 will be disposed interiorly underneath the wipercarrier pivot 448 in a position overlaying and trapping the sleeve 416between the two arms 465. In this manner, rotation of the wiper leverassembly 20 in a generally downward direction with respect to a normalmounting position on a vehicle steering column results in theaforementioned rotation of the wash/mist actuator 410 to actuate thevehicle windshield washer pump to spray windshield washer fluid onto thevehicle windshield. A return spring 466 is mounted in a recess in thefront cover 16 and acts on one of the arms 465 to bias the wiper lever462 back to the normal, centered position.

A wiper shaft 470 has a tubular shaft section terminating in a reduceddiameter first end 472. As shown in FIG. 3C, the first end 472 slidesthrough an opening at one end of the wiper lever 462 and through asleeve 474 on a wiper gear 476. The wiper gear 476 is similar to theheadlamp gear 254 in that an enlarged disk is mounted at one end of thesleeve 474 and has a plurality of teeth 478, each formed of a stem 477and spherical end portion 479, by example only, extending at least alonga predetermined arc or sector thereof. The spherical ends 479 of theteeth 478 engage the recesses 438 in the radial rack 436 and are capableof radial sliding movement upon pivotal movement of the lever 20 alongcertain axes as well as rotation to drive the radial rack 436. Aretainer, such as a wave clip 480, is mounted about the end of the firstend portion 472 of the wiper shaft 470 to secure the wiper shaft 470 tothe wiper gear 476. As the sleeve 474 of the wiper gear 476 rotatablyseats within a shoulder at one end of the wiper lever 462, the wipershaft 470, the wiper gear 476 and the wiper lever 462 are joinedtogether as an integral structure for pivotal and rotary movement asdescribed hereafter.

It is conventional to provide backlash in a mating gear pair. Backlashis defined as the amount by which the tooth space of one gear exceedsthe tooth thickness of the mating gear at the pitch circle of the gears.However, according to a unique aspect of the present invention, thedrive gear 476 and the recesses or teeth 438 on the radial rack 436 aredesigned with zero backlash. As shown in FIG. 16, the diameter or toothwidth of each tooth 478 on the drive gear 476, at the pitch circle ofeach tooth formed between adjacent recesses 438 in the radial rack 436is designed to be substantially the same as the tooth space betweenadjacent faces 437 and 439 forming one recess 438 in the radial rack436. This provide better timing accuracy for the wiper operationparticularly with a multi-axially oriented stalk lever gear pair 436,476 where the drive gear 476 rotates on one rotational axis for a wiperdrive operation, moves about another rotational axis for a windshieldwash operation, and operates along yet another rotational axis for amissed wiper operation.

According to another aspect of the present invention, the radial rack436 is provided with some flexibility along its rotational axis in orderto reduce friction and wear between the contact of the drive gear teeth478 and the recesses or tooth spaces 438 in the radial rack 436 when thedrive gear 476 is rotated. This flexibility is provided by the slide onmounting of the sleeve 442 over the post 98 on the grid assembly 88, asdescribed above, as well as preload or biasing force exerted on theradial rack 436 by the leaf contacts 94, 95 and 96, one of which isshown in FIG. 15. As described above, each of the leaf contacts 94, 95,96, such as the illustrated leaf contact 95, cantilevers from one end ofthe conductive traces or conductive elements in the grid assembly 88.The end of the leaf contact 95 is resiliently biased toward theconductive traces on the bottom surface of the radial rack 436, as alsodescribed above. This resilient or biasing force normally biases theradial rack 436 axially along the post 98 into firm contact with theteeth 478 of the drive gear 476.

The opposite end of the wiper shaft 470 is formed in a key-shaped end482 having a generally I-shape which fits within a complementary shapedrecess in a wiper cap 484. A pair of oppositely extending hollow sleeves486 project from the wiper shaft 470 adjacent to the key end 482. Thesleeves 486 are alignable with a pair of mounting legs 488, only one ofwhich is shown in FIG. 3D. A plunger and spring assembly formed of twooppositely extending plungers 492 and 493 biased outwardly by a spring494 extends through the aligned bores in the sleeves 486 with the outerends of the plungers 492 and 493 extending through the apertures 490 inthe mounting legs 488 of the wiper cap 484 to unitarily join the wipercap 484 to the wiper shaft 470. A reduced diameter shoulder 496 on oneend of the wiper lever 462 seats within the open end of the wiper cap484 and provides a bearing surface for rotation of the wiper cap 484relative to the wiper lever 462.

At least one of the plungers 492 and 393 extending outwardly through theapertures 490 in the mounting legs 488 of the wiper cap 484 engage adetent surface 498 formed on the interior of the one end of the wiperlever 462 which defines a series of spaced, discrete, positions of thewiper cap 484 relative to the wiper lever 462. Each discrete positionrepresents a different amount of arcuate movement of the radial rack 436and rotation of the wiper cap 484 to connect more or less of theresistors on the outer conductive trace 432 on the printed circuit board426 in a wiper speed circuit for an intermittent wiper controloperation.

From the above description, it can be seen that the wiper lever assembly20 functions to control windshield wiper speed via rotation of the wipercap 484 through a plurality of discrete positions defined by the detentsurface 498, and a windshield mist operation via downward rotation ofthe lever assembly 20 relative to the normal position of the front cover14 on a vehicle steering column which activates the wiper drive for onecycle and a simultaneous rotation of the vehicle windshield wipers.Finally, pivotal movement of the lever assembly 20 toward the driverresults in a downward movement on the wash/mist actuator 410 causing thelower end of the center member 416 to engage and depress a leaf contact97 pivotally carried on the grid assembly 88 into contact with anunderlying conductive trace of the grid assembly 88. This controls thewiper drive to operate the vehicle wipers for one cycle.

What is claimed is:
 1. In a vehicle steering column stalk switch havinga housing mountable on a vehicle steering column, a lever movablymounted on the housing and an actuator carried on the lever androtatable with respect to the lever, the improvement comprising: a firstgear having gear teeth, the first gear coupled to the actuator forrotation with rotation of the actuator; a second gear movably mounted inthe housing, the second gear having channel-shaped recesses; the gearteeth and the channel-shaped recesses normally engaged with zerobacklash, wherein movement of the lever slidingly moves the gear teethout of engagement with the recesses; conductive elements carried on oneof the second gear and the housing; and a contact formed on the other ofthe second gear and the housing, wherein rotation of the actuator causesrotation of the first gear and movement of the second gear toselectively engage the contact with selective conductive elements toopen and close electrical circuits therebetween.
 2. The improvement ofclaim 1, further comprising: means for biasing the first gear and thesecond gear into engagement.
 3. The improvement of claim 2 wherein themeans for biasing comprises: a leaf contact resiliently cantileveredfrom one of the second gear and the housing.
 4. The improvement of claim1 wherein the second gear is a radial rack mounted on a pivot shaftformed in the housing.
 5. A vehicle steering column stalk switchcomprising: a housing mountable on a vehicle steering column; a levermovably mounted on the housing; an actuator carried on the lever androtatable with respect to the lever; a first gear having first gearteeth, the first gear coupled to the actuator for rotation with rotationof the actuator; a second gear movably mounted in the housing, thesecond gear having second gear teeth; the first and second gear teeth ofthe first and second gears, respectively, engaged with zero backlash;conductive elements carried on one of the second gear and the housing; acontact formed on the other of the second gear and the housing, whereinrotation of the actuator causes rotation of the first gear and movementof the second gear to selectively engage the contact with selectiveconductive elements to open and close electrical circuits therebetween;and means for biasing the first and second gears into engagement.
 6. Thevehicle steering column stalk switch according to claim 5 wherein thesecond gear teeth are formed by channel-shaped recesses.
 7. The vehiclesteering column stalk switch according to claim 5 wherein the secondgear is a radial rack mounted on a pivot shaft formed in the housing. 8.The vehicle steering column stalk switch according to claim 7 whereinthe second gear teeth are formed by channel-shaped recesses in theradial rack.
 9. The vehicle steering column stalk switch according toclaim 5 wherein the means for biasing comprises: a leaf contactresiliently cantilevered from one of the second gear and the housing.10. The vehicle steering column stalk switch according to claim 5wherein movement of the lever moves the first gear teeth out ofengagement with the second gear teeth.
 11. A vehicle steering columnstalk switch comprising: a housing mountable on a vehicle steeringcolumn; a lever movably mounted on the housing; an actuator carried onthe lever and rotatable with respect to the lever; a first gear havingfirst gear teeth, the first gear coupled to the actuator for rotationwith rotation of the actuator; a second gear movably mounted in thehousing, the second gear having second gear teeth; the first and secondgear teeth of the first and second gears, respectively, engaged withzero backlash; conductive elements carried on second gear and thehousing; and a contact formed on the other of the second gear and thehousing, wherein rotation of the actuator causes rotation of the firstgear and movement of the second gear to selectively engage the contactwith selective conductive elements to open and close electrical circuitstherebetween, the contact formed as at least one leaf contactresiliently cantilevered from the conductive elements in the housing,the at least one leaf contact biasingly engaged with the second gear tobias the second gear into compliant engagement with the first gear. 12.The vehicle steering column stalk switch according to claim 11 whereinthe second gear teeth are formed by channel-shaped recesses.
 13. Thevehicle steering column stalk switch according to claim 11 wherein thesecond gear is a radial rack mounted on a pivot shaft formed in thehousing.
 14. The vehicle steering column stalk switch according to claim11 wherein movement of the lever moves the first gear teeth out ofengagement with the second gear teeth.